As long as you enjoy it, I am sure she would think that's fine!

When she was a child, and her birthday fell during Lent, she was not allowed a cake or party, which I objected to. So when she was elderly, I made sure we celebrated her birthday whether or not Easter had come. She was number 6 of 8 children, and several of the others had birthdays that fell outside the season, so they ALWAYS had cake.